From 9fee0ec4ca0c5b7a334cc29dbb58e76c7a4c736e Mon Sep 17 00:00:00 2001 From: Michiel Van Der Kolk Date: Mon, 11 Jul 2005 15:42:37 +0000 Subject: Songdb java version, source. only 1.5 compatible git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7101 a1c6a512-1295-4272-9138-f99709370657 --- songdbj/javazoom/jl/decoder/Bitstream.java | 655 +++++++++++++++++++++++++++++ 1 file changed, 655 insertions(+) create mode 100644 songdbj/javazoom/jl/decoder/Bitstream.java (limited to 'songdbj/javazoom/jl/decoder/Bitstream.java') diff --git a/songdbj/javazoom/jl/decoder/Bitstream.java b/songdbj/javazoom/jl/decoder/Bitstream.java new file mode 100644 index 0000000000..cebbd5b03b --- /dev/null +++ b/songdbj/javazoom/jl/decoder/Bitstream.java @@ -0,0 +1,655 @@ +/* + * 11/19/04 1.0 moved to LGPL. + * + * 11/17/04 Uncomplete frames discarded. E.B, javalayer@javazoom.net + * + * 12/05/03 ID3v2 tag returned. E.B, javalayer@javazoom.net + * + * 12/12/99 Based on Ibitstream. Exceptions thrown on errors, + * Temporary removed seek functionality. mdm@techie.com + * + * 02/12/99 : Java Conversion by E.B , javalayer@javazoom.net + * + * 04/14/97 : Added function prototypes for new syncing and seeking + * mechanisms. Also made this file portable. Changes made by Jeff Tsay + * + * @(#) ibitstream.h 1.5, last edit: 6/15/94 16:55:34 + * @(#) Copyright (C) 1993, 1994 Tobias Bading (bading@cs.tu-berlin.de) + * @(#) Berlin University of Technology + *----------------------------------------------------------------------- + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Library General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + *---------------------------------------------------------------------- + */ + +package javazoom.jl.decoder; + +import java.io.BufferedInputStream; +import java.io.ByteArrayInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.PushbackInputStream; + + +/** + * The Bistream class is responsible for parsing + * an MPEG audio bitstream. + * + * REVIEW: much of the parsing currently occurs in the + * various decoders. This should be moved into this class and associated + * inner classes. + */ +public final class Bitstream implements BitstreamErrors +{ + /** + * Synchronization control constant for the initial + * synchronization to the start of a frame. + */ + static byte INITIAL_SYNC = 0; + + /** + * Synchronization control constant for non-initial frame + * synchronizations. + */ + static byte STRICT_SYNC = 1; + + // max. 1730 bytes per frame: 144 * 384kbit/s / 32000 Hz + 2 Bytes CRC + /** + * Maximum size of the frame buffer. + */ + private static final int BUFFER_INT_SIZE = 433; + + /** + * The frame buffer that holds the data for the current frame. + */ + private final int[] framebuffer = new int[BUFFER_INT_SIZE]; + + /** + * Number of valid bytes in the frame buffer. + */ + private int framesize; + + /** + * The bytes read from the stream. + */ + private byte[] frame_bytes = new byte[BUFFER_INT_SIZE*4]; + + /** + * Index into framebuffer where the next bits are + * retrieved. + */ + private int wordpointer; + + /** + * Number (0-31, from MSB to LSB) of next bit for get_bits() + */ + private int bitindex; + + /** + * The current specified syncword + */ + private int syncword; + + /** + * Audio header position in stream. + */ + private int header_pos = 0; + + /** + * + */ + private boolean single_ch_mode; + //private int current_frame_number; + //private int last_frame_number; + + private final int bitmask[] = {0, // dummy + 0x00000001, 0x00000003, 0x00000007, 0x0000000F, + 0x0000001F, 0x0000003F, 0x0000007F, 0x000000FF, + 0x000001FF, 0x000003FF, 0x000007FF, 0x00000FFF, + 0x00001FFF, 0x00003FFF, 0x00007FFF, 0x0000FFFF, + 0x0001FFFF }; + + private final PushbackInputStream source; + + private final Header header = new Header(); + + private final byte syncbuf[] = new byte[4]; + + private Crc16[] crc = new Crc16[1]; + + private byte[] rawid3v2 = null; + + private boolean firstframe = true; + + + /** + * Construct a IBitstream that reads data from a + * given InputStream. + * + * @param in The InputStream to read from. + */ + public Bitstream(InputStream in) + { + if (in==null) throw new NullPointerException("in"); + in = new BufferedInputStream(in); + loadID3v2(in); + firstframe = true; + //source = new PushbackInputStream(in, 1024); + source = new PushbackInputStream(in, BUFFER_INT_SIZE*4); + + closeFrame(); + //current_frame_number = -1; + //last_frame_number = -1; + } + + /** + * Return position of the first audio header. + * @return size of ID3v2 tag frames. + */ + public int header_pos() + { + return header_pos; + } + + /** + * Load ID3v2 frames. + * @param in MP3 InputStream. + * @author JavaZOOM + */ + private void loadID3v2(InputStream in) + { + int size = -1; + try + { + // Read ID3v2 header (10 bytes). + in.mark(10); + size = readID3v2Header(in); + header_pos = size; + } + catch (IOException e) + {} + finally + { + try + { + // Unread ID3v2 header (10 bytes). + in.reset(); + } + catch (IOException e) + {} + } + // Load ID3v2 tags. + try + { + if (size > 0) + { + rawid3v2 = new byte[size]; + in.read(rawid3v2,0,rawid3v2.length); + } + } + catch (IOException e) + {} + } + + /** + * Parse ID3v2 tag header to find out size of ID3v2 frames. + * @param in MP3 InputStream + * @return size of ID3v2 frames + header + * @throws IOException + * @author JavaZOOM + */ + private int readID3v2Header(InputStream in) throws IOException + { + byte[] id3header = new byte[4]; + int size = -10; + in.read(id3header,0,3); + // Look for ID3v2 + if ( (id3header[0]=='I') && (id3header[1]=='D') && (id3header[2]=='3')) + { + in.read(id3header,0,3); + int majorVersion = id3header[0]; + int revision = id3header[1]; + in.read(id3header,0,4); + size = (int) (id3header[0] << 21) + (id3header[1] << 14) + (id3header[2] << 7) + (id3header[3]); + } + return (size+10); + } + + /** + * Return raw ID3v2 frames + header. + * @return ID3v2 InputStream or null if ID3v2 frames are not available. + */ + public InputStream getRawID3v2() + { + if (rawid3v2 == null) return null; + else + { + ByteArrayInputStream bain = new ByteArrayInputStream(rawid3v2); + return bain; + } + } + + /** + * Close the Bitstream. + * @throws BitstreamException + */ + public void close() throws BitstreamException + { + try + { + source.close(); + } + catch (IOException ex) + { + throw newBitstreamException(STREAM_ERROR, ex); + } + } + + /** + * Reads and parses the next frame from the input source. + * @return the Header describing details of the frame read, + * or null if the end of the stream has been reached. + */ + public Header readFrame() throws BitstreamException + { + Header result = null; + try + { + result = readNextFrame(); + // E.B, Parse VBR (if any) first frame. + if (firstframe == true) + { + result.parseVBR(frame_bytes); + firstframe = false; + } + } + catch (BitstreamException ex) + { + if ((ex.getErrorCode()==INVALIDFRAME)) + { + // Try to skip this frame. + //System.out.println("INVALIDFRAME"); + try + { + closeFrame(); + result = readNextFrame(); + } + catch (BitstreamException e) + { + if ((e.getErrorCode()!=STREAM_EOF)) + { + // wrap original exception so stack trace is maintained. + throw newBitstreamException(e.getErrorCode(), e); + } + } + } + else if ((ex.getErrorCode()!=STREAM_EOF)) + { + // wrap original exception so stack trace is maintained. + throw newBitstreamException(ex.getErrorCode(), ex); + } + } + return result; + } + + /** + * Read next MP3 frame. + * @return MP3 frame header. + * @throws BitstreamException + */ + private Header readNextFrame() throws BitstreamException + { + if (framesize == -1) + { + nextFrame(); + } + return header; + } + + + /** + * Read next MP3 frame. + * @throws BitstreamException + */ + private void nextFrame() throws BitstreamException + { + // entire frame is read by the header class. + header.read_header(this, crc); + } + + /** + * Unreads the bytes read from the frame. + * @throws BitstreamException + */ + // REVIEW: add new error codes for this. + public void unreadFrame() throws BitstreamException + { + if (wordpointer==-1 && bitindex==-1 && (framesize>0)) + { + try + { + source.unread(frame_bytes, 0, framesize); + } + catch (IOException ex) + { + throw newBitstreamException(STREAM_ERROR); + } + } + } + + /** + * Close MP3 frame. + */ + public void closeFrame() + { + framesize = -1; + wordpointer = -1; + bitindex = -1; + } + + /** + * Determines if the next 4 bytes of the stream represent a + * frame header. + */ + public boolean isSyncCurrentPosition(int syncmode) throws BitstreamException + { + int read = readBytes(syncbuf, 0, 4); + int headerstring = ((syncbuf[0] << 24) & 0xFF000000) | ((syncbuf[1] << 16) & 0x00FF0000) | ((syncbuf[2] << 8) & 0x0000FF00) | ((syncbuf[3] << 0) & 0x000000FF); + + try + { + source.unread(syncbuf, 0, read); + } + catch (IOException ex) + { + } + + boolean sync = false; + switch (read) + { + case 0: + sync = true; + break; + case 4: + sync = isSyncMark(headerstring, syncmode, syncword); + break; + } + + return sync; + } + + + // REVIEW: this class should provide inner classes to + // parse the frame contents. Eventually, readBits will + // be removed. + public int readBits(int n) + { + return get_bits(n); + } + + public int readCheckedBits(int n) + { + // REVIEW: implement CRC check. + return get_bits(n); + } + + protected BitstreamException newBitstreamException(int errorcode) + { + return new BitstreamException(errorcode, null); + } + protected BitstreamException newBitstreamException(int errorcode, Throwable throwable) + { + return new BitstreamException(errorcode, throwable); + } + + /** + * Get next 32 bits from bitstream. + * They are stored in the headerstring. + * syncmod allows Synchro flag ID + * The returned value is False at the end of stream. + */ + + int syncHeader(byte syncmode) throws BitstreamException + { + boolean sync; + int headerstring; + // read additional 2 bytes + int bytesRead = readBytes(syncbuf, 0, 3); + + if (bytesRead!=3) throw newBitstreamException(STREAM_EOF, null); + + headerstring = ((syncbuf[0] << 16) & 0x00FF0000) | ((syncbuf[1] << 8) & 0x0000FF00) | ((syncbuf[2] << 0) & 0x000000FF); + + do + { + headerstring <<= 8; + + if (readBytes(syncbuf, 3, 1)!=1) + throw newBitstreamException(STREAM_EOF, null); + + headerstring |= (syncbuf[3] & 0x000000FF); + + sync = isSyncMark(headerstring, syncmode, syncword); + } + while (!sync); + + //current_frame_number++; + //if (last_frame_number < current_frame_number) last_frame_number = current_frame_number; + + return headerstring; + } + + public boolean isSyncMark(int headerstring, int syncmode, int word) + { + boolean sync = false; + + if (syncmode == INITIAL_SYNC) + { + //sync = ((headerstring & 0xFFF00000) == 0xFFF00000); + sync = ((headerstring & 0xFFE00000) == 0xFFE00000); // SZD: MPEG 2.5 + } + else + { + sync = ((headerstring & 0xFFF80C00) == word) && + (((headerstring & 0x000000C0) == 0x000000C0) == single_ch_mode); + } + + // filter out invalid sample rate + if (sync) + sync = (((headerstring >>> 10) & 3)!=3); + // filter out invalid layer + if (sync) + sync = (((headerstring >>> 17) & 3)!=0); + // filter out invalid version + if (sync) + sync = (((headerstring >>> 19) & 3)!=1); + + return sync; + } + + /** + * Reads the data for the next frame. The frame is not parsed + * until parse frame is called. + */ + int read_frame_data(int bytesize) throws BitstreamException + { + int numread = 0; + numread = readFully(frame_bytes, 0, bytesize); + framesize = bytesize; + wordpointer = -1; + bitindex = -1; + return numread; + } + + /** + * Parses the data previously read with read_frame_data(). + */ + void parse_frame() throws BitstreamException + { + // Convert Bytes read to int + int b=0; + byte[] byteread = frame_bytes; + int bytesize = framesize; + + // Check ID3v1 TAG (True only if last frame). + //for (int t=0;t<(byteread.length)-2;t++) + //{ + // if ((byteread[t]=='T') && (byteread[t+1]=='A') && (byteread[t+2]=='G')) + // { + // System.out.println("ID3v1 detected at offset "+t); + // throw newBitstreamException(INVALIDFRAME, null); + // } + //} + + for (int k=0;k>> (32 - sum)) & bitmask[number_of_bits]; + // returnvalue = (wordpointer[0] >> (32 - sum)) & bitmask[number_of_bits]; + if ((bitindex += number_of_bits) == 32) + { + bitindex = 0; + wordpointer++; // added by me! + } + return returnvalue; + } + + // E.B : Check that ? + //((short[])&returnvalue)[0] = ((short[])wordpointer + 1)[0]; + //wordpointer++; // Added by me! + //((short[])&returnvalue + 1)[0] = ((short[])wordpointer)[0]; + int Right = (framebuffer[wordpointer] & 0x0000FFFF); + wordpointer++; + int Left = (framebuffer[wordpointer] & 0xFFFF0000); + returnvalue = ((Right << 16) & 0xFFFF0000) | ((Left >>> 16)& 0x0000FFFF); + + returnvalue >>>= 48 - sum; // returnvalue >>= 16 - (number_of_bits - (32 - bitindex)) + returnvalue &= bitmask[number_of_bits]; + bitindex = sum - 32; + return returnvalue; +} + + /** + * Set the word we want to sync the header to. + * In Big-Endian byte order + */ + void set_syncword(int syncword0) + { + syncword = syncword0 & 0xFFFFFF3F; + single_ch_mode = ((syncword0 & 0x000000C0) == 0x000000C0); + } + /** + * Reads the exact number of bytes from the source + * input stream into a byte array. + * + * @param b The byte array to read the specified number + * of bytes into. + * @param offs The index in the array where the first byte + * read should be stored. + * @param len the number of bytes to read. + * + * @exception BitstreamException is thrown if the specified + * number of bytes could not be read from the stream. + */ + private int readFully(byte[] b, int offs, int len) + throws BitstreamException + { + int nRead = 0; + try + { + while (len > 0) + { + int bytesread = source.read(b, offs, len); + if (bytesread == -1) + { + while (len-->0) + { + b[offs++] = 0; + } + break; + //throw newBitstreamException(UNEXPECTED_EOF, new EOFException()); + } + nRead = nRead + bytesread; + offs += bytesread; + len -= bytesread; + } + } + catch (IOException ex) + { + throw newBitstreamException(STREAM_ERROR, ex); + } + return nRead; + } + + /** + * Simlar to readFully, but doesn't throw exception when + * EOF is reached. + */ + private int readBytes(byte[] b, int offs, int len) + throws BitstreamException + { + int totalBytesRead = 0; + try + { + while (len > 0) + { + int bytesread = source.read(b, offs, len); + if (bytesread == -1) + { + break; + } + totalBytesRead += bytesread; + offs += bytesread; + len -= bytesread; + } + } + catch (IOException ex) + { + throw newBitstreamException(STREAM_ERROR, ex); + } + return totalBytesRead; + } +} -- cgit v1.2.3